Field effect transistors (FETs) are often combined with Schottky diodes in electronic circuits for synchronizing and the like. For example, in synchronous rectification applications, e.g. in DC to DC power supplies, current conducting diodes are needed because the current waveform applied to the FET is not always perfectly synchronized to the gate drive waveform. Current practice is to use a discrete diode and connect it in parallel to the FET and included in a common package. Employing discrete diodes results in relatively large size, weight, cost, and device parasitics. The relatively large parasitics result in poor switching speeds.
An alternate approach that is beginning to be used in silicon MOSFET technology is to use a silicon Schottky diode integrated with a silicon double diffused metal on semiconductor field effect transistor (DMOSFET). See for example U.S. Pat. No. 4,811,065, entitled "Power DMOS Transistor With High Speed Body Diode", issued Mar. 7, 1989. The difficulty here is that the double diffusion process is limited to a silicon semiconductor material.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide an integrated vertical field effect transistor and Schottky diode.
Another object of the invention is to provide an integrated vertical field effect transistor and Schottky diode which has reduced size, weight, cost, and device parasitics.
And another object of the invention is to provide a method of fabricating an integrated vertical field effect transistor and Schottky diode.
Yet another object of the present invention is to provide a method of fabricating an integrated vertical field effect transistor and Schottky diode without increasing fabrication steps.
And yet another object of the present invention is to provide a method of fabricating an integrated vertical field effect transistor and Schottky diode in improved semiconductor materials.